1. Field of the Invention
This invention relates to internal combustion engines and, more particularly, to an air filter having a choke valve and spitback shield.
2. Prior Art
Various different types of choke valves and spitback shields are known in the internal combustion engine art. In Andreasson, U.S. Pat. No. 4,495,911 a choke device located in the air filter of an internal combustion engine is disclosed. U.S. Pat. No. 1,105,090 discloses an air valve for carburetors. U.S. Pat. No. 4,539,162 discloses a choke assembly for a golf cart. U.S. Pat. No. 3,746,320 discloses a fuel feed and charge forming method and apparatus with an inlet region having a choke band of a venturi-like shape.
However, various different problems still exist with presently available devices. First, it is desirous to substantially reduce or eliminate contamination of the filter elements in the air filter by fuel spitback. Spitback can generally be described as the ejection of fuel particles out of the carburetor air intake into the air filter. Spitback can contaminate the air filter element causing dust particles and the like to become caked on the filter elements and prevent a proper air-fuel mixture from being obtained. Second, in some situations, it is desirous to provide components as small or compact as possible such as for reduction in the size and weight of the engine. This is particularly important for hand held devices such as chain saws or grass trimmers.
It is therefore an objective of the present invention to provide an air filter having an airflow controller that is laterally movably mounted in the air filter for a relatively small and compact combined air filter and airflow controller.
It is a further objective of the present invention to provide an airflow controller for use in an air filter that can restrict airflow into carburetor and also act as a spitback shield to protect the filter element of the air filter.